The invention relates to an apparatus for measuring physiological parameters, the apparatus having a test chamber connected to at least one inlet opening and at least one outlet opening and bordered by walls, wherein at least one wall of the test chamber is constructed as a semiconductor chip, which has an active side having planar sensors facing the test chamber, on which biological cells located in a nutrient medium can be adherently deposited, in order to measure physiological parameters directly on the cells, and wherein at least one additional sensor is allocated to a wall lying opposite the semiconductor chip in order to measure global physiological parameters.
Such an apparatus is already known from German published patent application DE 44 17 079 A1. It has a test chamber in which animal or plant biological cells can be kept vital in a nutrient medium over a long time period. There, the nutrient medium can be renewed through the inlet and outlet openings of the test chamber, for example using a fluid treatment. In the test chamber the cells are deposited adherently on the active side of the semiconductor chip having the planar sensors. For this purpose, the semiconductor chip can have, for example, on its active side a surface structuring, whose roughness corresponds approximately to the coarseness of the cells, so that they accept the semiconductor chip as neighbors and become better accumulated thereon.
The planar sensors allow an almost continuously flat chip surface, so that the cells can become deposited directly onto the planar sensors. It is thereby possible with the planar sensors to measure directly on the cells physical, electrical, or electrochemical cell parameters, for example ion concentrations, gas contents, cell potentials, or cell temperatures. Thus, the reaction of the cells can be tested in a simple manner for changed physical or chemical conditions, for example toxic substances, drugs, environmental toxins and the like contained in the nutrient medium. The cells thereby act as biological pre-amplifiers, which increase the measuring sensitivity of the planar sensors. Using the additional sensors allocated to the wall lying opposite the semiconductor chip, it is also possible to detect global physiological parameters in the nutrient medium. In this manner, additional information can be obtained about the cells.
Although the previously known apparatus has proven to be useful in practice, it nevertheless has disadvantages. It is still constructed in a comparatively complicated manner. The apparatus is therefore relatively expensive, which limits its usage possibilities.